Laser welding system

ABSTRACT

The laser welding system including a welding frame for receiving a first steel plate to be welded thereupon, at least one first clamping member to be installed above the welding frame, for fixing the first steel plate received on the welding frame, at least one second clamping member for fixing a second steel plate to be welded in close vicinity to a position at which the first steel plate is to be engaged with and welded with the second steel plate, an anvil on which the second steel plate is received, for moving the second steel plate to the position at which the first steel plate is to be engaged with and welded with the second steel plate, and a laser welding head for welding the first and second steel plates at the position at which the first steel plate is to be welded with the second steel plate. The first and second clamping members and anvil are operated by air bags.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a laser welding system, and moreparticularly to a laser welding system in which by minimizing the gapsof the engaging surfaces based on the operations of the clamping membersand the anvils when a tailored blanks utilized in industrial structureare welded, the engaging surfaces of the engaging portions becomestable. Thus, since the welding is accomplished with rapidity and ease,improving the qualities of the welding portions and enhancing thereliability of the structure, and the equipment lines are simple, andthereby reducing the manufacturing cost of the welding object anddecreasing the welding time.

2. Description of the Prior Art

A tailored blank is a member manufactured by butt-welding two steelplates of different thickness by laser welding. The tailored blank ismolded by a press or a roll-molding device, and is used in the body, thedoor, and the bumper of a car. Therefore, a high quality is needed inthe tailored blank, and the tailored blank needs mass-producing.

Currently, Nothelfer Co. of Germany, Sudronic Co. Of Swiss, and VIL Co.of the U.S. manufacture welding systems for producing tailored blanks.

The welding system of Nothelfer Co. feeds two steel plates from a frontside in a chain manner. The two fed steel plates are pressed by rollers,and are butt-welded according to a welding line, and a laser beam headis fixed to the welding device.

The welding system of Sudronic Co. uses a shuttle in which two steelplates are butted to accomplish the welding, and a laser beam head isfixed to the welding device. The welding system employs a gap removingmanner named Souka, which rolls thick steel plates to bridge the gap.

In the welding system of VIL Co., two steel plates are fed from the bothsides of the system respectively, and are butted together, and a laserbead head welds the plates. In the welding system of VIL Co., the twoplates are arranged by using pins so as to butt each other, and aseparate device is used to bridge the gap.

However, in the welding system of VIL Co., since the welded tailoredblank is fed reversibly in a direction, the tailor blanks cannot becontinuously manufactured. Furthermore, since two rows of pins are usedto arrange the steel plates in a welding line, the number of parts andassembling processes are increased. Moreover, since clamping members areintegrally formed, problems can occur when over two plates are welded.

Furthermore, in the welding systems of Sudronic Co. and VIL Co., inorder to accurately arrange pins in the welding lines, the systemsshould be precisely machined. Since the engaging portions are notstable, fine defects and foreign substances can be formed in the weldedsurfaces, and thereby decreasing the overall durability of the weldingstructures.

SUMMARY OF THE INVENTION

The present invention has been made to solve the aforementioned problem,and accordingly, it is an object of the present invention to provide alaser welding system in which by bridging the gaps of the engagingsurfaces based on the operations of the clamping members and the anvilswhen a tailored blanks used industrial structure are welded, theengaging surfaces of the engaging portions become stable. Thus, thewelding is accomplished rapidly and easily, and thereby improving thequalities of the welding portions and enhancing the reliability of thestructure, and the equipment lines are simple, and thereby reducing themanufacturing cost of the welding object and lessening the welding time.

In order to achieve the aforementioned object of the present invention,the present invention provides a laser welding system comprising: awelding frame for receiving a first steel plate to be welded thereupon;at least one first clamping member installed above the welding frame,for fixing the first steel plate received on the welding frame; at leastone second clamping member for fixing a second steel plate to be weldedin close vicinity to a position at which the first steel plate is to beengaged with and welded with the second steel plate; an anvil on whichthe second steel plate is received, for moving the second steel plate tothe position at which the first steel plate is to be engaged with andwelded with the second steel plate; and a laser welding head for weldingthe first and second steel plates at the position at which the firststeel plate is to be welded with the second steel plate.

Preferably, the laser welding system further comprises a first uppersupport, a second support, a first air bag provided between the firstupper support and the first clamping member, for inflating when thefirst clamping member fixes the first steel plate, and a second air bagprovided between the second upper support and the second clampingmember, for inflating when the second clamping member fixes the secondsteel plate.

Preferably, the laser welding system further comprises a first aircylinder installed at the first upper support, for separating the firstclamping member from the first steel plate after the welding iscompleted, and a second air cylinder installed at the second uppersupport, for separating the second clamping member from the second steelplate after the welding is made.

Preferably, the laser welding system further comprises means for movingthe anvil towards the position at which the first steel plate is to bewelded with the second steel plate, so that the anvil moves the secondplate to the position at which the first steel plate is to be engagedwith and welded with the second steel plate.

Preferably, the means for moving the anvil comprises a lower support, apivoting member engaged with a third hinge and having one side fixed tothe anvil, and a third air bag provided between the lower support andthe pivoting member, for inflating to pivot the pivoting member when theanvil is moved to a position at which the first steel plate is to bewelded with the second steel plate.

Preferably, the means for moving the anvil further comprises a third aircylinder installed at the lower support, for moving the anvil to aninitial position after the welding is completed.

Preferably, the third air bag is shrunk after the welding is completed,and the third air cylinder presses one side of the pivoting member tomove the anvil to the initial position.

Preferably, the first clamping member has a first thickness that isthick enough not to bend when the first clamping member is operated, andthe second clamping member has a second thickness that is thin enough tobend when the second clamping member is operated.

Preferably, portions of the first and second clamping members at whichthe first and second clamping members are engaged with the first andsecond steel plates have saw-teeth respectively.

Preferably, a portion of the anvil has saw-teeth so that the secondsteel plate should not slide from the anvil when the anvil moves thesecond steel plate to the position at which the first steel plate is tobe engaged with and welded with the second steel plate.

Preferably, a plurality of first clamping members, a plurality of secondclamping members, and a plurality of anvils are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the present invention willbecome readily apparent by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a side view for showing a laser welding system according to apreferred embodiment of the present invention;

FIG. 2 is a plan view of a welding object, which is manufactured by thelaser welding system shown in FIG. 1;

FIG. 3 is a side view of a welding object that is manufactured by thelaser welding system shown in FIG. 1;

FIG. 4 is a side view for showing a portion of the laser welding systemshown in FIG. 1 in detail;

FIG. 5 represents side views showing the operations of the secondclamping member and the anvil of the laser welding system shown in FIG.1;

FIG. 6 is a side view showing a welding object which is manufactured bythe laser welding system according to another preferred embodiment ofthe present invention; and

FIG. 7 is a side view showing another welding object that ismanufactured by the laser welding system based on the preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, preferred embodiments of the present invention will beexplained in detail with reference to the attached drawings.

FIG. 1 is a side view showing a laser welding system based on thepreferred embodiment of the present invention. FIGS. 2 and 3 are sideand plan views showing a welding object that is manufactured by thelaser welding system shown in FIG. 2, respectively.

Referring to FIG. 1, the laser welding system according to the presentinvention includes a welding frame 110, a first clamping member 120, asecond clamping member 130, an anvil 140, and a laser welding head 112.

A first steel plate A to be welded is received on the welding frame. Thefirst clamping member fixes the first steel plate A received on thewelding frame 110, and is installed above the welding frame 110.

At least, one second clamping member 130 is installed to fix the secondsteel plate B to be welded in close vicinity to a position at which thefirst steel plate A is to be engaged with and welded with the secondsteel plate B.

The second steel plate B is received on the anvil 140, and the anvil 140moves the second steel plate B to the position at which the first steelplate A is to be engaged with and welded with the second steel plate B.

The first and second steel plates A and B which are engaged with eachother at the position at which the first steel plate A is to be weldedwith the second steel plate B are welded together by the laser weldinghead 112.

The laser welding system 100 further includes a first upper support 122,a second upper support 132, a first air bag 124, and a second air bag134.

The first air bag 124 is provided between the first upper support 122and the first clamping member 120. The first air bag 124 inflates topivot the first clamping member 120, when the first clamping member 120fixes the first steel plate A.

The second air bag 134 is provided between the second upper support 132and the second clamping member 130. The second air bag 124 inflates topivot the second clamping member 130, when the second clamping member130 fixes the second steel plate B.

The laser welding system 100 further includes a first air cylinder 126and a second air cylinder 136.

The first air cylinder 128 is installed at the first upper support 122,and separates the first clamping member 120 from the first steel plate Aafter the welding is completed. The second air cylinder 136 is installedat the second upper support 132, and separates the second clampingmember 120 from the second steel plate B after the welding is completed.

The first clamping member 120 is engaged with a first hinge 128, and thefirst air cylinder 126 presses one side of the first clamping member 120to separate the first clamping member 120 from the first steel plate A,after the welding is completed.

The second clamping member 130 is engaged with a second hinge 138, andthe second air cylinder 136 presses one side of the second clampingmember 130 to separate the second clamping member 130 from the secondsteel plate B, after the welding is completed.

The laser welding system 100 further comprises means for moving theanvil 140 towards the position at which the first steel plate A is to bewelded with the second steel plate B, so that the anvil 140 moves thesecond plate B to the position at which the first steel plate A is to beengaged with and welded with the second steel plate B.

The means for moving the anvil 140 comprises a lower support 142, apivoting member 143, and a third air bag.

The pivoting member 143 is engaged with a third hinge 148 and has oneside fixed to the anvil 140. The third air bag 144 is provided betweenthe lower support 142 and the pivoting member 143.

The third air bag 144 inflates to pivot the pivoting member 143, whenthe anvil 140 is moved to a position at which the first steel plate A isto be welded with the second steel plate B.

The means for moving the anvil 140 further comprises a third aircylinder 146 installed at the lower support 142, for moving the anvil140 to the initial position after the welding is completed.

The third air bag 144 is shrunk after the welding is completed, and thethird air cylinder 146 presses one side of the pivoting member 143 tomove the anvil 140 to the initial position.

FIG. 4 is a side view showing a portion of the laser welding systemshown in FIG. 1 in detail.

Referring to FIGS. 1 to 4, the first and second steel plates A and Bshown in FIGS. 2 and 3 are fed horizontally on the welding frame 110 andthe anvil 140, respectively. When the airs are filled in the first andsecond air bag 124 and 134, the first and second clamping members 120and 130 fixes the first and second steel plates A and B, respectively.In addition, when the third air bag 144 is filled with the air, theanvil 140 is operated to firmly engage the second steel plate B with thefirst steel plate A.

According to a preferred embodiment of the present invention, the firststeel plate A is firstly is received on ar d fixed to the welding frame110, and the second steel plate B is then received on and fixed to theanvil 140. This is made by the operations of a feeding device (notshown) and the first and second clamping members 120 and 130, which isoperated based on the operations of the first and second air bags 124and 134 respectively.

Referring to FIG. 4, the first clamping member 120 has a first thicknessthat is thick enough not to bend even when the first clamping member 120is operated. The second clamping member 130 has a second thickness thatis thin enough to bend when the second clamping member 130 is operated.

As shown in FIG. 4, the portions of the first and second clampingmembers 120 and 130 at which the first and second clamping members 120and 130 are engaged with the first and second steel plates A and B havesaw-teeth respectively.

The saw-teeth prevent the first and second steel plates A and B fromslipping when the first and second clamping members 120 and 130 fix thefirst and second steel plates A and B, and help the engagement of thefirst and second steel plates A and B.

Further, as shown in FIG. 4, a portion of the anvil 140 has saw-teeth.The saw-teeth of the anvil prevent the second steel plate B from slidingfrom the anvil 140 when the anvil 140 moves the second steel plate B tothe position at which the first steel plate A is to be engaged with andwelded with the second steel plate B.

Therefore, the second steel plate B is closely engaged with the firststeel plate B, and the operations of the first and second clampingmembers 120 and 130, and the anvil 140 minimize the gap of the engagingportions at which the first and second steel plates A and B are engaged.

FIG. 5 are side views showing the operations of the second clampingmember and the anvil of the laser welding system shown in FIG. 1.

As shown in FIG. 5, the first steel plate A is fixed on the weldingframe 110 by the operation of the first clamping member 120, and thenthe second steel plate B is engaged with the first steel plate A. Beforethe operation of the second clamping member 130, the second clampingmember 130 is at α-angle with the second steel plate B.

Then, if the second clamping member 130 is operated by the operation ofthe second air bag 134 and the pivotal movement of the pivoting member143 operates the anvil 140, the second member 130 is at β-angle with thesecond steel plate B, and the β-angle is smaller than the α-angle. Then,the second clamping member 130 is resiliently bent.

FIG. 6 is a side view for showing a welding object that is manufacturedby the laser welding system according to another preferred embodiment ofthe present invention. FIG. 7 is a side view for showing another weldingobject that is manufactured by the laser welding system according to thepreferred embodiment of the present invention.

As shown in FIG. 7, according to a preferred embodiment of the presentinvention, a plurality of first clamping members 120, a plurality ofsecond clamping members 130, and a plurality of anvils 140 are provided.Therefore, different first clamping members 120, different secondclamping members 130, and different anvils 140 are operated according tothe engaging positions.

Referring to FIG. 6, in order to butt-weld the stapler-shaped steelplate D, E, and F and another steel plate G, the steel plate D and E iswelded to the steel plate F. Therefore, there exist welding lines R2 andR3 in the stapler-shaped steel plate D, E, and F, and the welding linesshould be R5 and R6 when the steel plate D, E, and F is welded to thesteel plate G.

However, the stapler-shaped steel plate D, E, and F is tortured when itis welded, and the welding lines becomes H. In this case, the weldingcannot be properly performed because of the gap portions.

Generally, the laser welding can be effectively accomplished only whenthe gaps of the engaging portions are smaller than 0.1 mm. Therefore,the gaps of the engaging portions should be removed.

In settle the above-mentioned problem, a technology in which after the Hportions of the stapler-shaped steel plate D, E, and F is precisely cut,the steel plate D, E, and F and the steel plate F is welded isdisclosed. However, the cutting process is troublesome, and the unitaccording to the technology becomes complex.

According to the laser welding system according to the presentinvention, the above-mentioned problem is settled by the operations of aplurality of the second clamping members 130 and a plurality of anvils140.

After the steel plate G is fixed on the welding frame 110 by theplurality of first clamping members 120, if the plurality of secondclamping members 130 and the plurality of anvils 140 are operated, thegaps in the engaging portions between the steel plate D, E, and F andthe steel plate G is disappeared. This is possible because the anvil 140located at a position in which the gap is larger proceeds further, andthe corresponding second clamping member 130 is much more bent. At aposition in which the gap is smaller, the anvil 140 proceeds less, andthe corresponding second clamping member 130 is less bent.

According to experiments, the laser welding system 100 according to thepresent invention effectively accomplishes the welding even when the gapis over 3 mm. Therefore, the laser welding system according to thepresent invention is remarkable in the tailored blank manufacturingtechnology.

The present invention can be applied to a steel plate having severalvertical steel plate as well as the stapler-shaped steel plate D, E, andF. FIG. 7 illustrates the positions of the first and second clampingmembers 120 and 130 in the case.

As above-described, according to the laser welding system of the presentinvention, by minimizing the gaps of the engaging surfaces according tothe operations of the clamping members and the anvils when a tailoredblanks used industrial structure are welded, the engaging surfaces ofthe engaging portions become stable, and thus the welding isaccomplished rapidly and easily, thereby improving the qualities of thewelding portions and enhancing the reliability of the structure.Further, the equipment lines are simple, thereby reducing themanufacturing cost of the welding object and shortening the weldingtime.

As stated above, preferred embodiments of the present invention areshown and described. Although the preferred embodiments of the presentinvention have been described, it is understood that the presentinvention should not be confined to these preferred embodiments butvarious changes and modifications can be made by one skilled in the artwithin the spirit and the scope of the present invention as claimedbelow.

What is claimed is:
 1. A laser welding system comprising: a weldingframe for receiving a first steel plate to be welded thereupon; at leastone first clamping member installed above the welding frame, for fixingthe first steel plate received on the welding frame; at least one secondclamping member for fixing a second steel plate to be welded in thevicinity of a position at which the first steel plate is to be engagedwith and welded with the second steel plate; an anvil on which thesecond steel plate is received for moving the second steel plate to theposition at which the first steel plate is to be engaged with and weldedwith the second steel plate; a laser welding head for welding the firstand second steel plates at the position at which the first steel plateis to be welded with the second steel plate; and means for moving theanvil towards the position at which the first steel plate is to bewelded with the second steel plate, so that the anvil moves the secondplate to the position at which the first steel plate is to be engagedwith and welded with the second steel plate, said anvil moving meansincluding a lower support, a pivoting member engaged with a third hingeand having one side fixed to the anvil, and and a third air bag pivotingmember when the anvil is moved to a position at which the first steelplate is to be welded with the second steelplate.
 2. A laser weldingsystem according to claim 1, further comprising a first upper support, asecond support, a first air bag provided between the first upper supportand the first clamping member, for inflating when the first clampingmember fixes the first steel plate, and a second air bag providedbetween the second upper support and the second clamping member, forinflating when the second clamping member fixes the second steel plate.3. A laser welding system according to claim 2, further comprising afirst air cylinder installed at the first upper support, for separatingthe first clamping member from the first steel plate after the weldingis completed, and a second air cylinder installed at the second uppersupport, for separating the second clamping member from the second steelplate after the welding is completed.
 4. A laser welding systemaccording to claim 3, wherein the first clamping member is engaged witha first hinge, and the first air cylinder presses one side of the firstclamping member to separate the first clamping member from the firststeel plate after the welding is completed, whereas the second clampingmember is engaged with a second hinge, and the second air cylinderpresses one side of the second clamping member to separate the secondclamping member from the second steel plate after the welding iscompleted.
 5. A laser welding system according to claim 1, wherein aportion of the anvil has saw-teeth so that the second steel plate shouldnot slide from the anvil when the anvil moves the second steel plate tothe position at which the first steel plate is to be engaged with andwelded with the second steel plate.
 6. A laser welding system accordingto claim 1, wherein a plurality of first clamping members, a pluralityof second clamping members, and a plurality of anvils are provided.
 7. Alaser welding system based on the claim 1, wherein the means for movingthe anvil further comprises a third air cylinder installed at the lowersupport, for moving the anvil to an initial position after the weldingis completed.
 8. A laser welding system based on the claim 7, whereinthe third air bag is shrunk after the welding is completed, and thethird air cylinder presses one side of the pivoting member to move theanvil to the initial position.
 9. A laser welding system according toclaim 1, wherein the first clamping member has a first thickness whichis thick enough not to bend when the first clamping member is operated,and the second clamping member has a second thickness which is thinenough to bend when the second clamping member is operated.
 10. A laserwelding system according to claim 1, wherein portions of the first andsecond clamping members at which the first and second clamping membersare engaged with the first and second steel plates have saw-teethrespectively.